1. Field of the Invention
Exhaust systems for vehicles generally include an exhaust manifold which is attached to an engine. The engine is generally resiliently mounted to a vehicle frame. An exhaust system further generally includes an exhaust outlet member which is rigidly mounted to the vehicle frame. Since the manifold is resiliently mounted to the frame via the engine and the exhaust outlet member is rigidly mounted to the frame, the manifold and the outlet member, in use, often vibrate and otherwise move in an uncontrolled manner relative to one another. The present invention is concerned with an improved slip joint connection between the manifold and the outlet member which assures full flow connection without significant leakage despite the relative vibrations and other movements of the manifold and the exhaust outlet member.
2. Prior Art
A particularly severe problem is present in off-highway trucks and the like, wherein the exhaust of the engine of the truck is directed from the engine manifold into channels in the truck frame because of the severe jolting and shaking to which off-highway trucks are subjected. The exhaust manifold of such a truck is in the usual manner supported by the engine which is itself resiliently held to the truck frame. The truck frame, or an exhaust outlet member which accepts the exhaust from the manifold and is attached to the truck frame, clearly does not move or vibrate in the same manner as does the manifold because of the resilient mounting of the latter. The connection of the manifold to the exhaust outlet member must thus be flexible but must still have long life. Further, the connection must be fully sealed throughout the vibrations and other movements of the truck. Still further, the connection is desirably such that the exhaust from the manifold is not in any way passed through a restriction even under maximum misalignment conditions so that back pressure on the engine is not produced. It is also highly desirable that the connection between the manifold and the exhaust outlet member be such that it provides compensation for any initial misalignment between the engine (and hence the manifold) and the truck frame (and hence the exhaust outlet member). Such initial misalignment is common due to manufacturing tolerances and variances in assembling the many parts of the engine and the frame. Easy assembly of the manifold - connection - exhaust outlet member is likewise highly desirable.
Similar problems arise in other apparatus which include a fluid flow source, such as an exhaust manifold, and a fluid exhaust member, such as an exhaust outlet member, and in which these are mounted in adjacent non-rigid relation to one another with at least one of said source and said member being subjected to limited vibratory and other motions relative to the other.
Flexible hose connections provide one prior art solution to the above stated problems. However, flexible hose connections tend to deteriorate with use. For example, if such connections are made of fully metallic members, metal fatigue tends to develop, and if such connections are made of rubber or plastic members, the heat of the exhaust gasses which are directed through them tend to more or less swiftly deteriorate them. Still further the installation of such flexible members generally requires a fairly large separation of the fluid flow source from the fluid exhaust member if the full advantage of their flexibility is to be realized, i.e. there must be enough of the flexible member between the fluid flow source and the fluid exhaust member so that it can adequately flex, and this is not always possible in close fitting situations.